= Collagen IV NC1 hexamer
{c}
A <Collagen IV NC1 hexamer> is a six-subunit junction formed when the <C-terminus> ends of two <Collagen IV protomers> associate. Each three-chain protomer contributes three <Collagen IV NC1 domains>. The resulting arrangement is therefore two three-subunit ends joined together, one local connection in a <basement membrane> scaffold.<A Sulfilimine Bond Identified in Collagen IV by Roberto Vanacore and others>[Introduction and Figure 3; trimeric ends and six-subunit junction]{ref}
Up to six <sulfilimine bonds> can reinforce the interface between the two ends. Analysis of linked <peptides> by <mass spectrometry> and <nuclear magnetic resonance>, followed by chemical reduction that separated the linked components, established the chemistry of this reinforcement.<A Sulfilimine Bond Identified in Collagen IV by Roberto Vanacore and others>[Table 1 and Figures 1–3; crosslinked peptides, bond identification and reduction]{ref}
This provides a useful distinction between subunit counting and bond counting. Six subunits describes the intact junction's architecture; the number of reinforcing links is another property. Neither number implies that a single <Collagen IV protomer> has six <polypeptide> chains.
Back to article page
